1. Field of the Invention
The present invention relates to a radiation detecting apparatus used as a medial radiation diagnostic apparatus, a nondestructive inspection apparatus, and the like, and a radiation imaging system using the same.
2. Description of the Related Art
In recent years, digitalization of X-ray radiographing has been accelerating, and a variety of radiation detecting apparatuses have been proposed. Such apparatuses are mainly divided into two system types, a direct system, that is, a type of directly converting the X-rays into electrical signals and reading the same, and an indirect system, that is, a type of converting the X-rays into visible light and then converting the visible light into the electrical signals and reading the same.
Japanese Patent Application Laid-Open No. 2004-033659 discloses a radiation detecting apparatus of the direct system.
As a light source main body, a cold-cathode tube is used, or a member aligning a plurality of LEDs to allow surface-emission in a pseudo-manner is available. On the other hand, a light generator 7 was once configured separately by a light source main body and a light diffusion film, but it is now available also in an arrangement in which it is integrally configured by an EL (electroluminescence) panel and the like.
A light generator having such a configuration irradiates an almost uniform light across the entire surface of the light receiving surface of an X-ray flat panel detector. The light irradiated by the light generator is generated at an appropriate timing before and after radiographing an object, and is used for repairing sensitivity deterioration caused due to an X-ray conversion layer comprising a semiconductor layer.
Further, Japanese Patent Application Laid-Open No. 2002-040144 discloses a radiation detecting apparatus of the indirect type. This apparatus is configured by a phosphor for converting the X-rays into visible light, a photoelectric conversion panel disposed on an insulating substrate and comprising a plurality of photoelectric conversion elements detecting the visible light, a light source (LED) disposed at the backside of the insulating substrate, and light generating means comprising a light guide.
The light from light generating means is irradiated onto the photoelectric conversion element comprising a semiconductor such as amorphous silicon and the like, and is used for preventing characteristic fluctuations that may arise due to long-term use and an increase in dark current due to a trap level generated within the semiconductor film. As a light source, for example, LED, EL, semiconductor laser, cold-cathode tube, and the like are used.
Further, U.S. Patent Application Publication No. 2005/0230629 discloses a radiation detecting apparatus of the indirect system. This apparatus comprises a semiconductor layer which converts radiation information into charge information by the incidence of the radiation, an active matrix substrate laminated with this semiconductor layer on the surface and reading the charge information from this semiconductor layer, light irradiating means for irradiating a light, and sheet light guiding means disposed on the rear surface side of the active matrix substrate and receiving the light from light irradiating means from an end surface side and guiding it to the semiconductor layer through the active matrix substrate. This apparatus comprises an electromagnetic shield for shielding noises radiated from the light irradiating means between the light irradiating means and the active matrix substrate in an area where the light irradiating means is opposed to the active matrix substrate.